A multi-phase boost conversion device

Abstract

A multiphase boost converter includes a multiphase boost converter and a passive lossless buffer. The passive lossless buffer includes a first resonant capacitor, a second resonant capacitor, a first unidirectional conducting element at the output terminal, a second unidirectional conducting element at the output terminal, a first unidirectional conducting element at the input terminal, a second unidirectional conducting element at the input terminal, and a resonant inductor. The advantage of this invention is that it reduces switching losses and electromagnetic interference in the multiphase boost converter by utilizing a buffer with a simple structure.

Description

Technical Field

[0001] The present invention is a multiphase boost converter with a buffer, and more particularly a multiphase boost converter with a passive lossless buffer. Background Technology

[0002] Two-phase hard-switching boost converters produce a significant overlap area between voltage and current on the voltage and current waveforms during switching. This overlap area is the switching loss, which reduces energy conversion efficiency and increases component temperature.

[0003] Later, a two-phase soft-switching boost converter was proposed, which reduced the overlap area of ​​the voltage and current, thereby reducing energy loss. Existing two-phase soft-switching boost converters reduce switching losses by slowing down the rise or fall slope of the switching voltage or current.

[0004] However, some existing two-phase soft-switching boost converters have high conduction losses and can only operate when the duty cycle is less than 50%. Some existing two-phase soft-switching boost converters cannot achieve 180-degree phase interleaving when the duty cycle is less than 50%. In addition, some related two-phase soft-switching boost converters have an excessive number of switching elements. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a multiphase boost converter with a passive lossless buffer.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A multiphase boost converter includes: a multiphase boost converter; and a passive lossless buffer electrically connected to the multiphase boost converter, wherein the passive lossless buffer includes: a first resonant capacitor electrically connected to the multiphase boost converter; a second resonant capacitor electrically connected to the multiphase boost converter; an output terminal first unidirectional conducting element electrically connected to the multiphase boost converter and the first resonant capacitor; an output terminal second unidirectional conducting element electrically connected to the multiphase boost converter and the second resonant capacitor; an input terminal first unidirectional conducting element electrically connected to the first resonant capacitor and the output terminal first unidirectional conducting element; an input terminal second unidirectional conducting element electrically connected to the second resonant capacitor and the output terminal second unidirectional conducting element; and a resonant inductor electrically connected to the multiphase boost converter, the input terminal first unidirectional conducting element, and the input terminal second unidirectional conducting element.

[0007] Compared with existing technologies, the advantage of this invention lies in reducing switching losses and electromagnetic interference in multiphase boost converters by utilizing a buffer with a simple structure. This invention can absorb spikes and slow down the rise rate of the switching voltage after the multiphase boost converter is switched off, thereby reducing the electromagnetic interference emission intensity caused by the high voltage slope and reducing switching losses during switch-off (i.e., the overlapping area of ​​the switching voltage and current on the voltage and current waveform). Attached Figure Description

[0008] Figures 1-1 to 1-8 These are schematic diagrams of the multiphase boost converter of the present invention in the first to eighth operating stages of the half-type.

[0009] Figures 2-1 to 2-8 These are schematic diagrams of the multiphase boost converter of the present invention in the first to eighth operating stages of the entire model.

[0010] Figure 3 This is a block diagram of the multiphase boost converter of the present invention.

[0011] Figure 4 The waveform diagrams are shown for the multiphase boost converter of the present invention from the first operating stage to the eighth operating stage of the half-type.

[0012] Figure 5 The waveform diagrams are shown for the multiphase boost converter of the present invention from the first operating stage to the eighth operating stage.

[0013] In the diagram: 10: Multiphase boost converter, 102: Multiphase boost converter, 104: Passive lossless buffer, 106: Switch controller, 108: Output terminal, 110: Input terminal, 112: Pulse width modulation signal, C1: First resonant capacitor, C2: Second resonant capacitor, Cin: Input capacitor, Co: Output capacitor, Coss1: First parasitic capacitance, Coss2: Second parasitic capacitance, D1: First diode, D2: Second diode, D3: First unidirectional conducting element at the input terminal, D4: Second unidirectional conducting element at the input terminal. Conducting element, D5: first unidirectional conducting element at the output terminal, D6: second unidirectional conducting element at the output terminal, iC1: first resonant capacitor current, iC2: second resonant capacitor current, iD1: first diode current, iD2: second diode current, iD3: first unidirectional conducting current at the input terminal, iD4: second unidirectional conducting current at the input terminal, iD5: first unidirectional conducting current at the output terminal, iD6: second unidirectional conducting current at the output terminal, ids1: first drain current, ids2: second drain current, iL1: first inductor current, iL1_pk: first... Inductor peak current, iL1_vly: first inductor trough current, iL2: second inductor current, iL2_pk: second inductor peak current, iL2_vly: second inductor trough current, iLs: resonant inductor current, L1: first inductor, L2: second inductor, LS: resonant inductor, OFF: transistor switch off, ON: transistor switch on, Q1: first transistor switch, Q2: second transistor switch, t0: zero time point, t1: first time point, t2: second time point, t3: third time point, t4: fourth time point Time points: t5: fifth time point, t6: sixth time point, t7: seventh time point, vC1: first resonant capacitor voltage, vC2: second resonant capacitor voltage, vds1: first drain voltage, vds2: second drain voltage, vgs1: first gate-source voltage, vgs2: second gate-source voltage, Vin: input voltage, vL1: first inductor voltage, vL2: second inductor voltage, vLs: resonant inductor voltage, Vo: output voltage, XC1: first resonant capacitor capacitive reactance, XC2: second resonant capacitor capacitive reactance, XLs: resonant inductor inductive reactance. Detailed Implementation

[0014] This disclosure provides numerous specific details to give a thorough understanding of specific embodiments of the invention; however, those skilled in the art will recognize that the invention can be practiced without one or more of these specific details; in other instances, well-known details have not been shown or described to avoid obscuring the key technical features of the invention. The technical content and detailed description of the invention are explained below in conjunction with the accompanying drawings:

[0015] Please refer to Figure 3The multiphase boost converter 10 includes a multiphase boost converter 102 and a passive lossless buffer (also known as a shock absorber) 104; the passive lossless buffer 104 includes a first resonant capacitor C1, a second resonant capacitor C2, an input first unidirectional conducting element D3, an input second unidirectional conducting element D4, an output first unidirectional conducting element D5, an output second unidirectional conducting element D6, and a resonant inductor LS; the multiphase boost converter 102 includes a first inductor L1, a second inductor L2, a first transistor switch Q1, a second transistor switch Q2, a first diode D1, a second diode D2, a switch controller 106, an output terminal 108, an input terminal 110, an input capacitor Cin, and an output capacitor Co; the first transistor switch Q1 has a first parasitic capacitance Coss1, and the second transistor switch Q2 has a second parasitic capacitance Coss2; all of the above components are electrically connected to each other.

[0016] For ease of explanation, this invention assumes that all the above-mentioned components are ideal and that the forward bias voltage of all the diodes is zero volts. The first unidirectional conducting element D3, the second unidirectional conducting element D4, the first unidirectional conducting element D5, and the second unidirectional conducting element D6 at the input terminal can be, for example, but are not limited to, diodes; the first transistor switch Q1 and the second transistor switch Q2 can be, for example, but are not limited to, metal-oxide-semiconductor field-effect transistors; the switch controller 106 can be, for example, but is not limited to, a pulse width modulation signal controller.

[0017] Depending on the different load power requirements, the operation of the multiphase boost converter 10 of the present invention can be divided into half-type operation and full-type operation. The half-type operation includes eight operation stages (i.e., half-type first operation stage to half-type eighth operation stage), and the full-type operation also includes eight operation stages (i.e., full-type first operation stage to full-type eighth operation stage).

[0018] First, the operation of this half-type in the present invention is described in detail below:

[0019] Please refer to Figure 3When the switch controller 106 is configured to transmit a pulse width modulation signal 112 to the first transistor switch Q1 to drive the first transistor switch Q1 and a duty cycle of the pulse width modulation signal 112 is less than 50%, or when the switch controller 106 is configured to transmit the pulse width modulation signal 112 to the second transistor switch Q2 to drive the second transistor switch Q2 and the duty cycle of the pulse width modulation signal 112 is less than 50%, the multiphase boost converter 10 is configured to operate sequentially in the half-type first operation stage, half-type second operation stage, half-type third operation stage, half-type fourth operation stage, half-type fifth operation stage, half-type sixth operation stage, half-type seventh operation stage, and half-type eighth operation stage.

[0020] Figures 1-1 to 1-8 These are schematic diagrams of the multiphase boost converter of the present invention in the first to eighth operating stages of the half-type. The dashed arrows indicate the direction of current, and for simplicity, some have already appeared in... Figure 3 The components and symbols in Figures 1-1 to 1-8 The symbol "ON" next to these transistor switches indicates that the transistor switch is turned on, and the symbol "OFF" indicates that the transistor switch is turned off.

[0021] Please also refer to Figure 1-1 and Figure 3 When the multiphase boost converter 10 is configured to operate in the first half-operation phase, the switch controller 106 is configured to turn on the first transistor switch Q1 and keep the second transistor switch Q2 off, and the first inductor L1 is configured to be energized by the input voltage Vin of one of the input terminals 110 to store first electrical energy in the form of a first magnetic field, and the first inductor current iL1 flowing through the first inductor L1 gradually increases, and the resonant inductor LS and the first resonant capacitor C1... The input terminal voltage Vin is charged and resonates, and the first unidirectional conducting element D3 is configured to cause the resonant inductor LS and the first resonant capacitor C1 to stop resonating after half a resonant cycle, such that the first resonant capacitor voltage vC1 of the first resonant capacitor C1 is twice the input terminal voltage Vin, and the resonant inductor current iLs flowing through the resonant inductor LS is zero, and then the multiphase boost converter 10 is configured to operate in the second half-operation phase.

[0022] Please also refer to Figure 1-2 and Figure 3When the multiphase boost converter 10 is configured to operate in the second half-type operation phase, the switch controller 106 is configured to keep the first transistor switch Q1 on and the second transistor switch Q2 off, and the first inductor L1 is configured to continue to be energized by the input voltage Vin, and the first inductor current iL1 continues to increase, and then the multiphase boost converter 10 is configured to operate in the third half-type operation phase.

[0023] Please also refer to Figure 1-3 and Figure 3 When the multiphase boost converter 10 is configured to operate in the third phase of the half-type operation, the switch controller 106 is configured to turn off the first transistor switch Q1 and keep the second transistor switch Q2 off, and the first parasitic capacitor Coss1 is configured to be charged from zero volts by the first inductor current iL1, causing the first source voltage vds1 of the first transistor switch Q1 to gradually increase, and the first resonant capacitor C1 is configured to discharge, causing the first single-phase output voltage to gradually increase. The conducting element D5 is configured to be forward biased, and the first resonant capacitor voltage vC1 discharges from twice the input terminal voltage Vin to zero volts, and the first source voltage vds1 plus the first resonant capacitor voltage vC1 equals one of the output terminal voltages Vo of the output terminal 108. When the first resonant capacitor voltage vC1 discharges to zero volts, the first diode D1 is configured to be forward biased, and then the multiphase boost converter 10 is configured to operate in the fourth operation phase of the half-type.

[0024] Please also refer to Figure 1-4 and Figure 3When the multiphase boost converter 10 is configured to operate in the fourth half-operation phase, the switch controller 106 is configured to keep the first transistor switch Q1 and the second transistor switch Q2 off, and the first diode D1 is configured to continue to be forward biased by the first inductor current iL1, the resonant inductor current iLs is zero, the first unidirectional current iD3 flowing through the first unidirectional conducting element D3 is zero, the second unidirectional current iD4 flowing through the second unidirectional conducting element D4 is zero, and the first resonant capacitor current iC1 flowing through the first resonant capacitor C1 is... The second resonant capacitor current iC2 flowing through the second resonant capacitor C2 is zero, the first unidirectional current iD5 flowing through the first unidirectional conducting element D5 at the output terminal is zero, and the second unidirectional current iD6 flowing through the second unidirectional conducting element D6 at the output terminal is zero (that is, no current flows through any of the components of the passive lossless buffer 104), and the first electrical energy stored in the first inductor L1 in the form of the first magnetic field is transmitted to the output terminal 108 in the form of current, and the first inductor current iL1 gradually decreases, and then the multiphase boost converter 10 is configured to operate in the fifth operation phase of the half-type.

[0025] Please also refer to Figure 1-5 and Figure 3 When the multiphase boost converter 10 is configured to operate in the fifth half-operation phase, the switch controller 106 is configured to turn on the second transistor switch Q2 and keep the first transistor switch Q1 off. The second inductor L2 is configured to be energized by the input voltage Vin to store second electrical energy in the form of a second magnetic field. The second inductance current iL2 flowing through the second inductor L2 gradually increases. The resonant inductor LS and the second resonant capacitor C2 are configured to be charged by the input voltage Vin and resonate. The second unidirectional conducting element D4 at the input terminal is configured to stop the resonant inductor LS and the second resonant capacitor C2 from resonating after half a cycle. The second resonant capacitor voltage vC2 of the second resonant capacitor C2 is twice the input voltage Vin, and the resonant inductance current iLs is zero. Then, the multiphase boost converter 10 is configured to operate in the sixth half-operation phase.

[0026] Please also refer to Figure 1-6 and Figure 3When the multiphase boost converter 10 is configured to operate in the sixth half-operation phase, the switch controller 106 is configured to keep the second transistor switch Q2 on and keep the first transistor switch Q1 off, and the second inductor L2 is configured to continue to be energized by the input voltage Vin, and the second inductor current iL2 continues to increase, and then the multiphase boost converter 10 is configured to operate in the seventh half-operation phase.

[0027] Please also refer to Figure 1-7 and Figure 3 When the multiphase boost converter 10 is configured to operate in the seventh half-type operation phase, the switch controller 106 is configured to turn off the second transistor switch Q2 and keep the first transistor switch Q1 off, and the second parasitic capacitor Coss2 is configured to be charged from zero volts by the second inductor current iL2, causing the second source voltage vds2 of the second transistor switch Q2 to gradually increase, and the second resonant capacitor C2 is configured to discharge, causing the second unidirectional conducting element D6 at the output terminal to be forward biased, and the second resonant capacitor voltage vC2 to discharge from twice the input terminal voltage Vin to zero volts, and the second source voltage vds2 plus the second resonant capacitor voltage vC2 equals the output terminal voltage Vo, and when the second resonant capacitor voltage vC2 discharges to zero volts, the second diode D2 is configured to be forward biased, and then the multiphase boost converter 10 is configured to operate in the eighth half-type operation phase.

[0028] Please also refer to Figure 1-8 and Figure 3 When the multiphase boost converter 10 is configured to operate in the eighth half-type operation phase, the switch controller 106 is configured to keep the second transistor switch Q2 off and the first transistor switch Q1 off, and the second diode D2 is configured to continue to be forward biased by the second inductor current iL2, the resonant inductor current iLs is zero, the first unidirectional current iD3 at the input terminal is zero, and the second unidirectional current iD4 at the input terminal is zero. The first resonant capacitor current iC1 is zero, the second resonant capacitor current iC2 is zero, the first unidirectional current iD5 at the output terminal is zero, and the second unidirectional current iD6 at the output terminal is zero (that is, no current flows through any of the components of the passive lossless buffer 104), and the second electrical energy stored in the second inductor L2 in the form of the second magnetic field is transmitted to the output terminal 108 in the form of current, and the second inductor current iL2 gradually decreases.

[0029] Please refer to Figure 4The waveform diagrams are shown for the multiphase boost converter of the present invention from the first to the eighth operating stages of the half-type; please also refer to... Figures 1-1 to 1-8 as well as Figure 3 In addition to the aforementioned component symbols, the first transistor switch Q1 has a first gate-source voltage vgs1, and the current flowing through the first transistor switch Q1 is called the first drain current ids1; the second transistor switch Q2 has a second gate-source voltage vgs2, and the current flowing through the second transistor switch Q2 is called the second drain current ids2; the current flowing through the first diode D1 is called the first diode current iD1; and the current flowing through the second diode D2 is called the second diode current iD2. The first inductor L1 has a first inductance voltage vL1, the second inductor L2 has a second inductance voltage vL2, and the resonant inductor LS has a resonant inductance voltage vLs. The peak current of the first inductor current iL1 is iL1_pk, the peak current of the second inductor current iL2 is iL2_pk, the trough current of the first inductor current iL1 is iL1_vly, and the peak current of the second inductor current iL2 is... The valley current is the second inductor valley current iL2_vly. The resonant inductor LS has a resonant inductive reactance XLs. The first resonant capacitor C1 has a first resonant capacitive reactance XC1. The second resonant capacitor C2 has a second resonant capacitive reactance XC2. The first operating phase of the half-type is between the zero time point t0 and the first time point t1. The second operating phase of the half-type is between the first time point t1 and the second time point t2. The third operating phase of the half-type is between the second time point t2 and the third time point t3. The fourth operating phase of the half-type is between the third time point t3 and the fourth time point t4. The fifth operating phase of the half-type is between the fourth time point t4 and the fifth time point t5. The sixth operating phase of the half-type is between the fifth time point t5 and the sixth time point t6. The seventh operating phase of the half-type is between the sixth time point t6 and the seventh time point t7. The eighth operating phase of the half-type is between the seventh time point t7 and the zero time point t0.

[0030] The full operation of this invention is described in detail below:

[0031] Please refer to the following: Figure 3When the switch controller 106 is configured to transmit the pulse width modulation signal 112 to the first transistor switch Q1 to drive the first transistor switch Q1 and the duty cycle of the pulse width modulation signal 112 is greater than or equal to 50%, or when the switch controller 106 is configured to transmit the pulse width modulation signal 112 to the second transistor switch Q2 to drive the second transistor switch Q2 and the duty cycle of the pulse width modulation signal 112 is greater than or equal to 50%, the multiphase boost converter 10 is configured to operate sequentially in the full-type first operation stage, full-type second operation stage, full-type third operation stage, full-type fourth operation stage, full-type fifth operation stage, full-type sixth operation stage, full-type seventh operation stage, and full-type eighth operation stage.

[0032] Figures 2-1 to 2-8 These are schematic diagrams of the multiphase boost converter of the present invention in the first to eighth operating stages of the entire system. The dashed arrows indicate the direction of current, and for simplicity, some have already appeared in... Figure 3 The components and symbols in Figures 2-1 to 2-8 The symbol "ON" next to these transistor switches indicates that the transistor switch is turned on, and the symbol "OFF" indicates that the transistor switch is turned off.

[0033] Please also refer to Figure 2-1 and Figure 3 When the multiphase boost converter 10 is configured to operate in the first phase of operation, the switch controller 106 is configured to turn on the first transistor switch Q1 and keep the second transistor switch Q2 on. The first inductor L1 is configured to be energized by the input voltage Vin of one of the input terminals 110 to store first electrical energy in the form of a first magnetic field, and the second inductor L2 is configured to be energized by the input voltage Vin to store second electrical energy in the form of a second magnetic field. The first inductance current iL1 flowing through the first inductor L1 gradually increases. The second inductor current iL2 flowing through the second inductor L2 gradually increases, and the resonant inductor LS and the first resonant capacitor C1 are configured to be charged and resonate by the input voltage Vin. The first inductor L1 is configured to be continuously energized by the input voltage Vin, causing the first inductor current iL1 to continuously increase. The second inductor L2 is configured to be continuously energized by the input voltage Vin, causing the second inductor current iL2 to continuously increase. Then, the multiphase boost converter 10 is configured to operate in the full-type second operation phase.

[0034] Please also refer to Figure 2-2 and Figure 3When the multiphase boost converter 10 is configured to operate in the second phase of the full-scale operation, the switch controller 106 is configured to keep the first transistor switch Q1 on and turn off the second transistor switch Q2, and the first inductor L1 is configured to continue to be energized by the input voltage Vin, and the first inductor current iL1 continues to increase, and the resonant inductor LS and the first resonant capacitor C1 are configured to be charged and resonate by the input voltage Vin, and the second parasitic capacitor Coss2 is configured to be charged from zero volts by the second inductor current iL2, so that the second source voltage vds2 of the second transistor switch Q2 gradually increases, and the second resonant capacitor C2 is configured to discharge, and the second source voltage vds2 plus the second resonant capacitor voltage vC2 of the second resonant capacitor C2 equals the output voltage Vo of one of the output terminals 108, and then the multiphase boost converter 10 is configured to operate in the third phase of the full-scale operation.

[0035] Please also refer to Figure 2-3 and Figure 3 When the multiphase boost converter 10 is configured to operate in the third phase of the full-cycle operation, the switch controller 106 is configured to keep the second transistor switch Q2 off and keep the first transistor switch Q1 on, and the first inductor L1 is configured to continue to be energized by the input voltage Vin, and the first inductor current iL1 continues to increase, and the resonant inductor LS and the first resonant capacitor C1 are configured to be charged and resonate by the input voltage Vin, and the first unidirectional conducting element D3 at the input terminal is configured to cause the resonant inductor LS and the first resonant capacitor C1 to stop resonating after half a cycle. The first resonant capacitor voltage vC1 of the first resonant capacitor C1 is twice the input terminal voltage Vin, and the resonant inductor current iLs flowing through the resonant inductor LS is zero. The second inductor current iL2 discharges to the second resonant capacitor C2. When the second resonant capacitor voltage vC2 discharges from twice the input terminal voltage Vin to zero volts, the second diode D2 is configured to be forward biased and turned on. The second source voltage vds2 plus the second resonant capacitor voltage vC2 equals the output terminal voltage Vo. Then the multiphase boost converter 10 is configured to operate in the fourth phase of the full-type operation.

[0036] Please also refer to Figure 2-4 and Figure 3When the multiphase boost converter 10 is configured to operate in the fourth phase of the full-scale operation, the switch controller 106 is configured to keep the second transistor switch Q2 off and keep the first transistor switch Q1 on, and the second diode D2 is configured to continue to be forward biased by the second inductor current iL2, and the resonant inductor current iLs is zero, and the first unidirectional conduction current iD3 flowing through the first unidirectional conduction element D3 at the input terminal is zero, and the second unidirectional conduction current iD4 flowing through the second unidirectional conduction element D4 at the input terminal is zero, and the first resonant capacitor current iC1 flowing through the first resonant capacitor C1 is zero, and the second resonant capacitor current iC1 flowing through the second resonant capacitor C2 is zero. The capacitor current iC2 is zero, and the first unidirectional current iD5 flowing through the first unidirectional conducting element D5 at the output terminal is zero, and the second unidirectional current iD6 flowing through the second unidirectional conducting element D6 at the output terminal is zero (i.e., no current flows through any of the components of the passive lossless buffer 104), and the second electrical energy stored in the second inductor L2 in the form of the second magnetic field is transferred to the output terminal 108 in the form of current, and the second inductor current iL2 gradually decreases, and the first inductor L1 is configured to be energized by the input voltage Vin, and the first inductor current iL1 increases, and then the multiphase boost converter 10 is configured to operate in the fifth operation phase of the full-type operation.

[0037] Please also refer to Figure 2-5 and Figure 3 When the multiphase boost converter 10 is configured to operate in the fifth phase of the full-cycle operation, the switch controller 106 is configured to turn on the second transistor switch Q2 and keep the first transistor switch Q1 on, and the first inductor L1 is configured to be energized by the input voltage Vin to store the first electrical energy in the form of the first magnetic field, and the second inductor L2 is configured to be energized by the input voltage Vin to store the second electrical energy in the form of the second magnetic field, and the first inductor current iL1 gradually increases, and the second inductor current iL2 gradually increases, and the resonant inductor LS and the second resonant capacitor C2 are configured to be charged by the input voltage Vin and resonate, and then the multiphase boost converter 10 is configured to operate in the sixth phase of the full-cycle operation.

[0038] Please also refer to Figure 2-6 and Figure 3When the multiphase boost converter 10 is configured to operate in the sixth phase of the full-cycle operation, the switch controller 106 is configured to keep the second transistor switch Q2 on and turn off the first transistor switch Q1, and the second inductor L2 is configured to continue to be energized by the input voltage Vin, and the second inductor current iL2 continues to increase. The first parasitic capacitor Coss1 is configured to be charged from zero volts by the first inductor current iL1, so that the first source voltage vds1 of the first transistor switch Q1 gradually increases, and the first resonant capacitor C1 is configured to discharge. The first source voltage vds1 plus the first resonant capacitor voltage vC1 equals the output voltage Vo, and then the multiphase boost converter 10 is configured to operate in the seventh phase of the full-cycle operation.

[0039] Please also refer to Figure 2-7 and Figure 3 When the multiphase boost converter 10 is configured to operate in the seventh phase of the full-scale operation, the switch controller 106 is configured to keep the second transistor switch Q2 on and the first transistor switch Q1 off, and the second inductor L2 is configured to continue to be energized by the input voltage Vin, and the second inductor current iL2 continues to increase, and the resonant inductor LS and the second resonant capacitor C2 are configured to be charged and resonate by the input voltage Vin, and the second unidirectional conducting element D4 at the input terminal is configured to make the resonant capacitor... The sensor LS and the second resonant capacitor C2 are configured to stop resonating after half a resonant cycle, such that the voltage of the second resonant capacitor vC2 is twice the input voltage Vin, and the resonant inductor current iLs is zero, and the first inductor current iL1 discharges to the first resonant capacitor C1. When the voltage of the first resonant capacitor vC1 discharges from twice the input voltage Vin to zero volts, the first diode D1 is configured to be forward biased and then the multiphase boost converter 10 is configured to operate in the eighth phase of the full-type operation.

[0040] Please also refer to Figure 2-8 and Figure 3When the multiphase boost converter 10 is configured to operate in the eighth phase of the full-cycle operation, the switch controller 106 is configured to keep the second transistor switch Q2 on and the first transistor switch Q1 off, and the first diode D1 is configured to continue to be forward biased by the first inductor current iL1, and the first inductor current iL1 is transmitted to the output terminal 108 for demagnetization, and the first inductor current iL1 gradually decreases, and the second inductor L2 is configured to be biased by the input voltage V. The second inductor current iL2 continuously increases due to continuous excitation, while the resonant inductor current iLs is zero, the first unidirectional current iD3 at the input terminal is zero, the second unidirectional current iD4 at the input terminal is zero, the first resonant capacitor current iC1 is zero, the second resonant capacitor current iC2 is zero, the first unidirectional current iD5 at the output terminal is zero, and the second unidirectional current iD6 at the output terminal is zero (i.e., no current flows through any of the components of the passive lossless buffer 104).

[0041] Please refer to Figure 5 The first action phase of the entire model is located between a zero time point t0 and a first time point t1; the second action phase of the entire model is located between the first time point t1 and a second time point t2; the third action phase of the entire model is located between the second time point t2 and a third time point t3; the fourth action phase of the entire model is located between the third time point t3 and the fourth time point t4; the fifth action phase of the entire model is located between the fourth time point t4 and the fifth time point t5; the sixth action phase of the entire model is located between the fifth time point t5 and the sixth time point t6; the seventh action phase of the entire model is located between the sixth time point t6 and the seventh time point t7; and the eighth action phase of the entire model is located between the seventh time point t7 and the zero time point t0.

[0042] The advantage of this invention lies in reducing switching losses and electromagnetic interference in multiphase boost converters by utilizing a buffer with a simple structure. This invention can absorb spikes and slow down the rise rate of the switching voltage after the multiphase boost converter is switched off, thereby reducing the electromagnetic interference emission intensity caused by the high voltage slope and reducing switching losses during switch-off (i.e., the overlapping area of ​​the switching voltage and current on the voltage and current waveform).

[0043] The passive lossless buffer 104 of this invention achieves the aforementioned effects by comprising only four diodes, one inductor, and two capacitors. Furthermore, the first resonant capacitor C1, the second resonant capacitor C2, the first unidirectional conducting element D3 at the input end, the second unidirectional conducting element D4 at the input end, the first unidirectional conducting element D5 at the output end, the second unidirectional conducting element D6 at the output end, and the resonant inductor LS included in the passive lossless buffer 104 do not participate in the main power processing and are not on the power transmission path. This allows the passive lossless buffer 104 to require only a very low rated power of the components, thus reducing component size and additional costs. Based on experimental data, under the same peripheral component parameters and full-load efficiency, compared with a traditional RCD buffer, this invention can significantly reduce switching losses and electromagnetic interference.

[0044] However, the above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. All equivalent changes and modifications made in accordance with the claims of this invention should still fall within the scope of protection intended by this invention. The present invention may also have other embodiments. Without departing from the spirit and essence of the invention, those skilled in the art can make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims. In summary, the present invention possesses industrial applicability, novelty, and inventiveness, and its structure has not been seen in similar products or publicly used, fully meeting the requirements for an invention patent application. Therefore, this application is filed in accordance with the Patent Law.

Claims

1. A multiphase boost converter, characterized in that: It contains: Multiphase boost converter; and A passive lossless buffer is electrically connected to the multiphase boost converter. The passive lossless buffer includes: The first resonant capacitor is electrically connected to the multiphase boost converter; The second resonant capacitor is electrically connected to the multiphase boost converter; The first unidirectional conducting element at the output terminal is electrically connected to the multiphase boost converter and the first resonant capacitor; The second unidirectional conducting element at the output terminal is electrically connected to the multiphase boost converter and the second resonant capacitor; The first unidirectional conducting element at the input terminal is electrically connected to the first resonant capacitor and the first unidirectional conducting element at the output terminal; The input terminal second unidirectional conducting element is electrically connected to the second resonant capacitor and the output terminal second unidirectional conducting element; and A resonant inductor is electrically connected to the multiphase boost converter, the first unidirectional conduction element at the input terminal, and the second unidirectional conduction element at the input terminal. This multiphase boost converter includes: A first transistor switch is electrically connected to the first resonant capacitor; The second transistor switch is electrically connected to the second resonant capacitor; and The switch controller is electrically connected to the first transistor switch and the second transistor switch. When the switch controller is configured to transmit a pulse width modulation signal to the first transistor switch to drive the first transistor switch and the duty cycle of the pulse width modulation signal is less than 50%, or when the switch controller is configured to transmit the pulse width modulation signal to the second transistor switch to drive the second transistor switch and the duty cycle of the pulse width modulation signal is less than 50%, the multiphase boost converter is configured to operate sequentially in the half-type first operation stage, half-type second operation stage, half-type third operation stage, half-type fourth operation stage, half-type fifth operation stage, half-type sixth operation stage, half-type seventh operation stage, and half-type eighth operation stage; When the switch controller is configured to transmit the pulse width modulation signal to the first transistor switch to drive the first transistor switch and the duty cycle of the pulse width modulation signal is greater than or equal to 50%, or when the switch controller is configured to transmit the pulse width modulation signal to the second transistor switch to drive the second transistor switch and the duty cycle of the pulse width modulation signal is greater than or equal to 50%, the multiphase boost converter is configured to operate sequentially in the first, second, third, fourth, fifth, sixth, seventh, and eighth operation phases.

2. The multiphase boost converter according to claim 1, characterized in that: When the multiphase boost converter is configured to operate in the first operating phase of the half-type, the switch controller is configured to turn on the first transistor switch and keep the second transistor switch off, and then the multiphase boost converter is configured to operate in the second operating phase of the half-type. When the multiphase boost converter is configured to operate in the second half-type operation phase, the switch controller is configured to keep the first transistor switch on and keep the second transistor switch off, and then the multiphase boost converter is configured to operate in the third half-type operation phase.

3. The multiphase boost converter according to claim 2, characterized in that: When the multiphase boost converter is configured to operate in the third phase of the half-type operation, the switch controller is configured to turn off the first transistor switch and keep the second transistor switch off, and then the multiphase boost converter is configured to operate in the fourth phase of the half-type operation. When the multiphase boost converter is configured to operate in the fourth operation phase of the half-type, the switch controller is configured to keep the first transistor switch off and the second transistor switch off, and then the multiphase boost converter is configured to operate in the fifth operation phase of the half-type.

4. A multiphase boost converter according to claim 3, characterized in that: When the multiphase boost converter is configured to operate in the fifth operation phase of the half-type, the switch controller is configured to turn on the second transistor switch and keep the first transistor switch off, and then the multiphase boost converter is configured to operate in the sixth operation phase of the half-type. When the multiphase boost converter is configured to operate in the sixth phase of the half-type operation, the switch controller is configured to keep the second transistor switch on and keep the first transistor switch off, and then the multiphase boost converter is configured to operate in the seventh phase of the half-type operation.

5. A multiphase boost converter according to claim 4, characterized in that: When the multiphase boost converter is configured to operate in the seventh operation phase of the half-type, the switch controller is configured to turn off the second transistor switch and keep the first transistor switch off, and then the multiphase boost converter is configured to operate in the eighth operation phase of the half-type. When the multiphase boost converter is configured to operate in the eighth phase of the half-type operation, the switch controller is configured to keep the second transistor switch off and the first transistor switch off.

6. A multiphase boost converter according to claim 1, characterized in that: When the multiphase boost converter is configured to operate in the first full-cycle operation phase, the switch controller is configured to turn on the first transistor switch and keep the second transistor switch on, and then the multiphase boost converter is configured to operate in the second full-cycle operation phase. When the multiphase boost converter is configured to operate in the second phase of the full-cycle operation, the switch controller is configured to keep the first transistor switch on and turn off the second transistor switch, and then the multiphase boost converter is configured to operate in the third phase of the full-cycle operation.

7. A multiphase boost converter according to claim 6, characterized in that: When the multiphase boost converter is configured to operate in the third phase of the full-cycle operation, the switch controller is configured to keep the second transistor switch off and keep the first transistor switch on, and then the multiphase boost converter is configured to operate in the fourth phase of the full-cycle operation. When the multiphase boost converter is configured to operate in the fourth phase of the full-cycle operation, the switch controller is configured to keep the second transistor switch off and keep the first transistor switch on, and then the multiphase boost converter is configured to operate in the fifth phase of the full-cycle operation.

8. A multiphase boost converter according to claim 7, characterized in that: When the multiphase boost converter is configured to operate in the fifth phase of the full-cycle operation, the switch controller is configured to turn on the second transistor switch and keep the first transistor switch on, and then the multiphase boost converter is configured to operate in the sixth phase of the full-cycle operation. When the multiphase boost converter is configured to operate in the sixth phase of the full-cycle operation, the switch controller is configured to keep the second transistor switch on and turn off the first transistor switch, and then the multiphase boost converter is configured to operate in the seventh phase of the full-cycle operation.

9. A multiphase boost converter according to claim 8, characterized in that: When the multiphase boost converter is configured to operate in the seventh phase of the full-cycle operation, the switch controller is configured to keep the second transistor switch on and keep the first transistor switch off, and then the multiphase boost converter is configured to operate in the eighth phase of the full-cycle operation. When the multiphase boost converter is configured to operate in the eighth phase of the full-type operation, the switch controller is configured to keep the second transistor switch on and keep the first transistor switch off.

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